Processing of tablets, such as inspecting, marking, and/or laser drilling of tablets, is known in the art. Inspection units are typically configured to inspect and remove tablets from a conveyer mechanism that have been improperly processed in a previous processing operation. Previous processing operations may include marking the tablets with indicia, coloring the tablets, laser drilling holes in the tablets, and/or coating the tablets. These processing operations are typically completed upstream from the inspection unit such that the inspection unit may inspect if these processes have been properly completed.
For example, a variety of known devices have been developed for applying a gel coating to pellet-shaped articles. Typically, the pellet-shaped articles, e.g., tablets, are coated by having one side of the pellet-shaped article coated at a time. Often, due to a processing error, one or both sides of the pellet-shaped article are not coated at all or one side of the pellet-shaped article is coated twice. As a result, the pellet-shaped article has at least one side that is not properly coated with gel. It is important for the manufacturer to carefully inspect the pellet-shaped articles for defects, such as an improperly coated side of the article, before the pellet-shaped article is distributed to the consumer so as to ensure the quality of the product and hence protect the safety of the consumer.
An example of an inspection unit is shown in U.S. Pat. No. 5,085,510 (the '510 patent). The '510 patent discloses an inspection unit for detecting laser drilled holes in tablets. As shown in FIG. 1, individual tablet carriers 6 are provided that transport individual tablets 2 in a vertical position past two sets of cameras 12. The cameras 12 are oriented horizontally and analyze opposing sides of the tablets 2 based on predetermined selection criteria. The cameras 12 signal a separation means 24 to divert preselected tablets 2. One significant limitation of the above unit is that only one tablet can be analyzed by a set of cameras at a time. As a result, more than one set of cameras must be utilized to maximize the inspection rate. Moreover, each tablet carrier 6 is only capable of transporting one tablet, which is inspected on both sides thereof. Thus, the '510 patent suffers in that the feed rate is severely limited because only one row of tablets is fed through the inspection unit.
Moreover, each tablet carrier 6 is configured to hold a tablet around the rim in a vertical position. This arrangement does not enable the entire exterior surface of the tablet to be inspected because at least a portion of the tablet rim and at least a portion of the tablet belly band is covered by the tablet carrier 6.
Another example of an inspection unit is disclosed in U.S. Patent Application Publication No. 2004/0094050 (the '050 publication), incorporated herein by reference in its entirety. The '050 publication discloses carrier bars provided with one or more article receiving pockets that hold the article in a horizontal position. A throughhole extends through each pocket so that the article within each pockets is visible from an upper side of the carrier bar and an inner side of the carrier bar through the throughhole. This arrangement allows cameras of the inspection unit to view both sides of the article.
Each carrier bar is configured to hold an article around the rim in a horizontal position, which does not enable the entire exterior surface of the tablet to be inspected because at least a portion of the tablet rim and at least a portion of the tablet belly band is covered by the carrier bar.
Thus, there is a need in the art for an improved method and apparatus for transporting and processing tablets that does not suffer from the above-mentioned drawbacks.